1- Off-setting or "rotating" the bulbs in a Roto-Ray are an effort to create a different / wider light pattern that makes the warning light more noticeable. Depending on the amount of "rotation / off-setting" there can be more light visible when viewed from the side.
As long there is no change in the weight of each light fixture there should be no concerns about throwing the Roto-Ray out of balance by off-setting / "rotating" the lights. I'm sure there is "some" change in the amount of air resistance by rotating a light fixture but I doubt there is enough to cause an "out of balance" rotation concern.
I have seen a Roto-Ray light "out of balance" vibrating wildly during operation but that was caused by a customer modifying the unit on their own with a PAR halogen light bulb in one head and LED arrays in the other two heads. The different in weight between PAR bulb and the LED's caused enough vibration to crack the Roto-Ray mounting plate.
2- "Flush" mounting a Federal Q2B were the grille face of the siren is flush with the face of the bumper has a couple of advantages. First it helps in reducing the overall length of an apparatus, secondly it protects the siren more from damage. As long as there is sufficient air-flow into the front grille of the Federal Q2B there should be no reduction of sound output or quality. Behind the bumper is typically wide open under the deck plate. Manufacturers take great pains to ensure things like bumper boxes or the like are not in close proximity to the side grilles of the siren. Again we're not talking about a large airflow here. As for the Projector / Director Cones... I have no data that supports either way if they cause any diminished sound output from the siren.
My comments are from my observations....Your mileage may vary!
Tim W.
As long there is no change in the weight of each light fixture there should be no concerns about throwing the Roto-Ray out of balance by off-setting / "rotating" the lights. I'm sure there is "some" change in the amount of air resistance by rotating a light fixture but I doubt there is enough to cause an "out of balance" rotation concern.
I have seen a Roto-Ray light "out of balance" vibrating wildly during operation but that was caused by a customer modifying the unit on their own with a PAR halogen light bulb in one head and LED arrays in the other two heads. The different in weight between PAR bulb and the LED's caused enough vibration to crack the Roto-Ray mounting plate.
2- "Flush" mounting a Federal Q2B were the grille face of the siren is flush with the face of the bumper has a couple of advantages. First it helps in reducing the overall length of an apparatus, secondly it protects the siren more from damage. As long as there is sufficient air-flow into the front grille of the Federal Q2B there should be no reduction of sound output or quality. Behind the bumper is typically wide open under the deck plate. Manufacturers take great pains to ensure things like bumper boxes or the like are not in close proximity to the side grilles of the siren. Again we're not talking about a large airflow here. As for the Projector / Director Cones... I have no data that supports either way if they cause any diminished sound output from the siren.
My comments are from my observations....Your mileage may vary!
Tim W.
Mechanical engineers build weapons, whereas civil engineers build targets.
When the man at the door said," Alcohol, Tobacco and Firearms", I, naturally assumed it was a delivery!
When the man at the door said," Alcohol, Tobacco and Firearms", I, naturally assumed it was a delivery!
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